CHANGES IN THE BENTHOCENOSES STRUCTURE OF VOTKINSKOE RESERVOIR DURING ITS EXISTENCE (1964-2014)

Abstract

The article summarizes the monitoring data and shown changes in the structure of benthocenoses of the central part of Votkinsk reservoir (location «Okhansk»). Current investigation is made on the basis of Kama biological station during the existence of the reservoir (1964-2014). In the early years of a new reservoir bottom communities were dominated by oligochaetes (Tubificidae), so the Votkinsk reservoir is one of the few where wasn't «chironomus stage». In the second half of the 1980th in the zoobenthos of the reservoir, there is a significant decline of oligochaetes ratio and increases the abundance of molluscs. Since the beginning of the XXI century, the structure of benthic communities has changed: there was significant decrease in abundance of molluscs, in particular zebra mussel Dreissena polymorpha (Pallas). At the present stage of the Votkinsk reservoir existence is marked by a certain stabilization of the benthic communities structure, and the leading role (excluding molluscs) of chironomid.